Craig's List for Philadelphia this month lists this clean Peugeot 10 speed for $125.

http://philadelphia.craigslist.org/bik/1162516442.html

It's a 21" frame (standard). Looks like it's from the late '70's.

I noticed that 2 members of this thread live within easy driving distance of Philadelphia.

The Philadelphia Craig's List always seems to have a mixte for sale -- mostly bikes stored in houses and not ridden anymore.